Composition and organic light-emitting device including the same

ABSTRACT

A composition including a first compound represented by Formula 1 and a second compound represented by Formula 2 and an organic light-emitting device including the composition: 
     
       
         
         
             
             
         
       
     
     Formulae 1 and 2 may each be understood by referring to the descriptions thereof provided herein.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Applications Nos. 10-2019-0037214, filed on Mar. 29, 2019, and 10-2019-0136949, filed on Oct. 30, 2019, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which is incorporated herein in its entirety by reference.

BACKGROUND 1. Field

The present disclosure relates to a composition and an organic light-emitting device including the same.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices which produce full-color images. In addition, OLEDs have wide viewing angles and exhibit excellent driving voltage and response speed characteristics.

OLEDs include an anode, a cathode, and an organic layer between the anode and the cathode and including an emission layer. A hole transport region may be between the anode and the emission layer, and an electron transport region may be between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. These excitons transit from an excited state to a ground state to thereby generate light.

SUMMARY

Provided are a novel composition, and an organic light-emitting device including the same.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to an aspect of an embodiment, a composition may include a first compound and a second compound, wherein the first compound may include a compound represented by Formula 1, and the second compound may include a compound represented by Formula 2:

wherein,

-   -   Y₂ in Formula 1 may be C,     -   ring CY₂ in Formula 1 may be a C₅-C₆₀ carbocyclic group or a         C₁-C₆₀ heterocyclic group,     -   Ar₁ in Formula 2 may be a C₅-C₆₀ carbocyclic group unsubstituted         or substituted with at least one R₆₁ or a C₁-C₆₀ heterocyclic         group unsubstituted or substituted with at least one R₆₁,     -   Ar₂ in Formula 2 may be a π electron-depleted         nitrogen-containing C₁-C₆₀ cyclic group unsubstituted or         substituted with at least one R₆₂,     -   Ar₅ in Formula 2 may not be present or be a single bond, a         C₅-C₆₀ carbocyclic group unsubstituted or substituted with at         least one R₆₅ or a C₁-C₆₀ heterocyclic group unsubstituted or         substituted with at least one R₆₅,     -   n in Formula 2 may be 1, 2, or 3, and when n is 1, Ar₅ may not         be present,     -   a1 and a2 in Formula 2 may each independently be an integer from         0 to 5, and the sum of a1 and a2 may be 1 or greater,     -   ring CY₂ and ring CY₃ in Formula 2 may each independently be a         C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, and         ring CY₂ and ring CY₃ may optionally be linked to each other via         or a C₅-C₆₀ carbocyclic group unsubstituted or substituted with         at least one R₆₆ or a C₁-C₆₀ heterocyclic group unsubstituted or         substituted with at least one R₆₆,     -   R₁ to R₈, A₂₀, A₁ to A₇, R₂₀, R₃₀, R₆₁, R₆₂, R₆₅, and R₆₆ in         Formulae 1 and 2 may each independently be hydrogen, deuterium,         —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro         group, an amino group, an amidino group, a hydrazine group, a         hydrazone group, a carboxylic acid group or a salt thereof, a         sulfonic acid group or a salt thereof, a phosphoric acid group         or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl         group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a         substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted         or unsubstituted C₁-C₆₀ alkoxy group, a substituted or         unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or         unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or         unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or         unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or         unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted         C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀         arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl         group, a substituted or unsubstituted monovalent non-aromatic         condensed polycyclic group, a substituted or unsubstituted         monovalent non-aromatic condensed heteropolycyclic group,         —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇),         —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉),     -   b2 and b3 in Formula 2 may each independently be an integer from         0 to 20, when b2 is 2 or more, two or more R₂₀(s) may be         identical to or different from each other, and when b3 is 2 or         more, two or more R₃₀(s) may be identical to or different from         each other,     -   d2 may be an integer from 0 to 10, and when d2 is 2 or more, two         or more A₂₀(s) may be identical to or different from each other,     -   at least one of R₁ to R₈, A₂₀, or any combination thereof may         comprise at least one fluoro group (—F),     -   two or more of R₁ to R₈ and A₂₀ in Formula 1 may optionally be         linked to form a C₅-C₆₀ carbocyclic group which is unsubstituted         or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic         group which is unsubstituted or substituted with at least one         R_(1a),     -   two or more of A₁ to A₇ in Formula 1 may optionally be linked to         form a C₅-C₆₀ carbocyclic group which is unsubstituted or         substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic         group which is unsubstituted or substituted with at least one         R₁₀,     -   two or more of ring CY₂, ring CY₃, R₂₀, and R₃₀ in Formula 2 in         Formula 1 may optionally be linked to form a C₅-C₆₀ carbocyclic         group which is unsubstituted or substituted with at least one         R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or         substituted with at least one R_(1a),     -   R_(1a) may be understood by referring to the description of A₇         provided herein, and     -   a substituent of the substituted C₁-C₆₀ alkyl group, the         substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl         group, the substituted C₁-C₆₀ alkoxy group, the substituted         C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl         group, the substituted C₃-C₁₀ cycloalkenyl group, the         substituted C₂-C₁₀ heterocycloalkenyl group, the substituted         C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the         substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀         heteroaryl group, the substituted monovalent non-aromatic         condensed polycyclic group, and the substituted monovalent         non-aromatic condensed heteropolycyclic group may be:     -   deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino         group, an amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, C₁-C₆₀ alkoxy group, or any combination thereof;     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, or a C₁-C₆₀ alkoxy group, each substituted with         deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino         group, an amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅),         —Ge(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), —P(═O)(Q₁₈)(Q₁₉),         —P(Q₁₈)(Q₁₉), or any combination thereof;     -   a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, or a monovalent non-aromatic         condensed heteropolycyclic group, each unsubstituted or         substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H,         —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a         nitro group, an amino group, an amidino group, a hydrazine         group, a hydrazone group, a carboxylic acid group or a salt         thereof, a sulfonic acid group or a salt thereof, a phosphoric         acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀         alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a         C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅),         —Ge(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉),         —P(Q₂₈)(Q₂₉), or any combination thereof;     -   —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —Ge(Q₃₃)(Q₃₄)(Q₃₅),         —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉), or —P(Q₃₈)(Q₃₉); or     -   any combination thereof,     -   wherein Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may         each independently be hydrogen; deuterium; —F; —Cl; —Br; —I; a         hydroxyl group; a cyano group; a nitro group; an amidino group;         a hydrazine group; a hydrazone group; a carboxylic acid group or         a salt thereof; a sulfonic acid group or a salt thereof; a         phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group,         unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl         group, a C₆-C₆₀ aryl group, or any combination thereof; a C₂-C₆₀         alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a         C₃-C₁₀ cycloalkyl group; a C₂-C₁₀ heterocycloalkyl group; a         C₃-C₁₀ cycloalkenyl group; a C₂-C₁₀ heterocycloalkenyl group; a         C₆-C₆₀ aryl group, unsubstituted or substituted with deuterium,         a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination         thereof; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a         C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed         polycyclic group; or a monovalent non-aromatic condensed         heteropolycyclic group.

According to an aspect of another embodiment, an organic light-emitting device may include: a first electrode; a second electrode; and an organic layer disposed between the first electrode and the second electrode and including an emission layer, wherein the organic layer includes the composition the first compound and the second compound described above.

The composition may be included in the emission layer of the organic layer, and the first compound included in the emission layer may serve as a dopant.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

The FIGURE is a schematic cross-sectional view of an organic light-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the FIGURES, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present

It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, “a,” “an,” “the,” and “at least one” do not denote a limitation of quantity, and are intended to cover both the singular and plural, unless the context clearly indicates otherwise. For example, “an element” has the same meaning as “at least one element,” unless the context clearly indicates otherwise.

“Or” means “and/or.” As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the FIGURES It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the FIGURES For example, if the device in one of the FIGURES is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the FIGURE Similarly, if the device in one of the FIGURES is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.

“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features Moreover, sharp angles that are illustrated may be rounded Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.

A composition may include a first compound and a second compound, wherein the first compound may include a compound represented by Formula 1, and the second compound may include a compound represented by Formula 2:

The first compound may include one compound represented by Formula 1 only or at least two different compounds represented by Formula 1.

The second compound may include one compound represented by Formula 2 only or at least two different compounds represented by Formula 2.

Description of Formula 1

Y₂ in Formula 1 may be C.

A ring CY₁₂ in Formula 1 may be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group.

For example, the ring CY₁₂ in Formula 1 may be i) a third ring, ii) a fourth ring, iii) a condensed cyclic group in which two or more third rings are condensed with each other, iv) a condensed cyclic group in which two or more fourth rings are condensed with each other, or v) a condensed cyclic group in which at least one third ring is condensed with at least one fourth ring,

the third ring is a cyclopentane group, a cyclopentadiene group, a furan group, a thiophene group, a pyrrole group, a silole group, an indene group, a benzofuran group, a benzothiophene group, an indole group, a benzosilole group, an oxazole group, an isoxazole group, an oxadiazole group, an isoxadiazole group, an oxatriazole group, an isoxatriazole group, a thiazole group, an isothiazole group, a thiadiazole group, an isothiadiazole group, a thiatriazole group, an isothiatriazole group, a pyrazole group, an imidazole group, a triazole group, a tetrazole group, an azasilole group, a diazasilole group, or a triazasilole group, and

the fourth ring may be an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group (a norbornane group), a bicyclo[2.2.2]octane group, a cyclohexane group, a cyclohexene group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.

In one or more embodiments, the ring CY₁₂ in Formula 1 may be a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, a thiophene group, a furan group, a pyrrole group, a cyclopentadiene group, a silole group, a borole group, a phosphole group, a selenophene group, a germole group, a benzothiophene group, a benzofuran group, an indole group, an indene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzoselenophene group, a benzogermole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a fluorene group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzoselenophene group, a dibenzogermole group, a dibenzothiophene 5-oxide group, 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azabenzothiophene group, an azabenzofuran group, an azaindole group, an azaindene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzoselenophene group, an azabenzogermole group, an azadibenzothiophene group, an azadibenzofuran group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzoselenophene group, an azadibenzogermole group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isooxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, a 5,6,7,8-tetrahydroquinoline group, an adamantane group, a norbornane group, or a norbornene group.

In one or more embodiments, the ring CY₁₂ may be a benzene group, a naphthalene group, a 1, 2, 3, 4-tetrahydronaphthalene group, a thiophene group, a furan group, a pyrrole group, a cyclopentadiene group, a silole group, a benzothiophene group, a benzofuran group, an indole group, an indene group, a benzosilole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a fluorene group, or a dibenzosilole group.

In Formula 1, R₁ to R₈, A₂₀ and A₁ to A₇ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉). Q₁ to Q₉ may respectively be understood by referring to the descriptions of Q₁ to Q₉ provided herein.

In embodiments, A₂₀ in Formula 1 may include neither a fluoro group (—F) nor a cyano group. For example, A₂₀ may be a group that includes neither a fluoro group (—F) nor a cyano group.

In embodiments, in Formula 1, R₁ to R₈, A₂₀ and A₁ to A₇ may each independently be:

-   -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid or a salt         thereof, a sulfonic acid or a salt thereof, a phosphoric acid or         a salt thereof, —SF₅, a C₁-C₂₀ alkyl group, or a C₁-C₂₀ alkoxy         group;     -   a C₁-C₂₀ alkyl group or a C₁-C₂₀ alkoxy group, each substituted         with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,         —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an         amino group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a C₁-C₂₀ alkyl group, a deuterium-containing C₁-C₂₀         alkyl group, a fluorinated C₁-C₂₀ alkyl group, a cyclopentyl         group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl         group, an adamantyl group, a norbomenyl group, a cyclopentenyl         group, a cyclohexenyl group, a cycloheptenyl group, a         bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a         bicyclo[2.2.1]heptyl group (a norbornanyl group), a         bicyclo[2.2.2]octyl group, a (C₁-C₂₀ alkyl)cyclopentyl group, a         (C₁-C₂₀ alkyl)cyclohexyl group, a (C₁-C₂₀ alkyl)cycloheptyl         group, a (C₁-C₂₀ alkyl)cyclooctyl group, a (C₁-C₂₀         alkyl)adamantyl group, a (C₁-C₂₀ alkyl)norbomenyl group, a         (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀ alkyl)cyclohexenyl         group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a (C₁-C₂₀         alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.1]heptyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a silolanyl group, a phenyl         group, a (C₁-C₂₀ alkyl)phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, a 1,2,3,4-tetrahydronaphthyl         group, a pyridinyl group, a pyrimidinyl group, or any         combination thereof;     -   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantyl group, a norbornenyl group, a         cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl         group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl         group, a bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl         group, a silolanyl group, a phenyl group, a (C₁-C₂₀ alkyl)phenyl         group, a biphenyl group, a terphenyl group, a naphthyl group, a         1,2,3,4-tetrahydronaphthyl group, a fluorenyl group, a         phenanthrenyl group, an anthracenyl group, a fluoranthenyl         group, a triphenylenyl group, a pyrenyl group, a chrysenyl         group, a pyrrolyl group, a thiophenyl group, a furanyl group, an         imidazolyl group, a pyrazolyl group, a thiazolyl group, an         isothiazolyl group, an oxazolyl group, an isoxazolyl group, a         pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a         pyridazinyl group, an isoindolyl group, an indolyl group, an         indazolyl group, a purinyl group, a quinolinyl group, an         isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl         group, a quinazolinyl group, a cinnolinyl group, a carbazolyl         group, a phenanthrolinyl group, a benzimidazolyl group, a         benzofuranyl group, a benzothiophenyl group, an         isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, an imidazopyridinyl group, an         imidazopyrimidinyl group, an azacarbazolyl group, an         azadibenzofuranyl group, or an azadibenzothiophenyl group, each         unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I,         —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a         cyano group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a         deuterium-containing C₁-C₂₀ alkyl group, a fluorinated C₁-C₂₀         alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a         cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an         adamantyl group, a norbomenyl group, a cyclopentenyl group, a         cyclohexenyl group, a cycloheptenyl group, a         bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a         bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantyl group, a         (C₁-C₂₀ alkyl)norbomenyl group, a (C₁-C₂₀ alkyl)cyclopentenyl         group, a (C₁-C₂₀ alkyl)cyclohexenyl group, a (C₁-C₂₀         alkyl)cycloheptenyl group, a (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl         group, a (C₁-C₂₀ alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.1]heptyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a silolanyl group, a phenyl         group, a (C₁-C₂₀ alkyl)phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, a 1,2,3,4-tetrahydronaphthyl         group, a fluorenyl group, a phenanthrenyl group, an anthracenyl         group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl         group, a chrysenyl group, a pyrrolyl group, a thiophenyl group,         a furanyl group, an imidazolyl group, a pyrazolyl group, a         thiazolyl group, an isothiazolyl group, an oxazolyl group, an         isoxazolyl group, a pyridinyl group, a pyrazinyl group, a         pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an         indolyl group, an indazolyl group, a purinyl group, a quinolinyl         group, an isoquinolinyl group, a benzoquinolinyl group, a         quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a         carbazolyl group, a phenanthrolinyl group, a benzimidazolyl         group, a benzofuranyl group, a benzothiophenyl group, an         isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, an imidazopyridinyl group, an         imidazopyrimidinyl group, an azacarbazolyl group, an         azadibenzofuranyl group, an azadibenzothiophenyl group, or any         combination thereof; or     -   —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇),         —P(═O)(Q)(Q), or —P(Q₅)(Q₆),     -   Q₁ to Q₉ may each independently be:     -   —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂,         —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H or         —CD₂CDH₂; or     -   an n-propyl group, an isopropyl group, an n-butyl group, a         sec-butyl group, an isobutyl group, a tert-butyl group, an         n-pentyl group, a tert-pentyl group, a neopentyl group, an         isopentyl group, a sec-pentyl group, a 3-pentyl group, a         sec-isopentyl group, a phenyl group, a biphenyl group, or a         naphthyl group, each unsubstituted or substituted with         deuterium, a C₁-C₂₀ alkyl group, a phenyl group, or any         combination thereof. Herein, A₂₀ in Formula 1 may include         neither a fluoro group (—F) nor a cyano group.

In one or more embodiments, R₁ to R₈, A₂₀ and A₁ to A₇ in Formula 1 may each independently be hydrogen, deuterium, —F, a substituted or unsubstituted C₁-C₂₀ alkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted phenyl group, —Si(Q₃)(Q₄)(Q₅), or —Ge(Q₃)(Q₄)(Q₅). Herein, A₂₀ may include neither a fluoro group nor a cyano group.

In one or more embodiments, R₁ to R₈ and A₁ to A₇ in Formula 1 may each independently be:

-   -   hydrogen, deuterium, or —F;     -   a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀         heterocycloalkyl group, or a phenyl group, each unsubstituted or         substituted with deuterium, —F, C₁-C₂₀ alkyl group, a C₃-C₁₀         cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a phenyl         group, or any combination thereof; or     -   —Si(Q₃)(Q₄)(Q₅), or —Ge(Q₃)(Q₄)(Q₅).

In one or more embodiments, A₂₀ in Formula 1 may be:

-   -   hydrogen or deuterium;     -   a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀         heterocycloalkyl group, or a phenyl group, each unsubstituted or         substituted with deuterium, a C₁-C₂₀ alkyl group, a C₃-C₁₀         cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a phenyl         group, or any combination thereof; or     -   —Si(Q₃)(Q₄)(Q₅), or —Ge(Q₃)(Q₄)(Q₅).

The designation d2 in Formula 1 indicates the number of A₂₀(s), and may be an integer from 0 to 10. When d2 is 2 or more, two or more A₂₀(s) may be identical to or different from each other. For example, d2 may be an integer from 0 to 6.

In an exemplary embodiment, at least one of R₁ to R₈, A₂₀ or any combination thereof in Formula 1 may include at least one fluoro group (—F).

In an exemplary embodiment, at least one of R₁ to R₈ (for example, at least one of R₂ to R₈, or at least one of R₃ to R₈) of Formula 1 may include at least one fluoro group (—F).

In an exemplary embodiment, at least one of R₁ to R₈ (for example, at least one of R₂ to R₈, or at least one of R₃ to R₈) of Formula 1 may be a group including at least one fluoro group (—F).

In one or more embodiments, at least one of R₁ to R₈ in Formula 1 may each independently be:

-   -   a fluoro group (—F); or     -   a fluorinated C₁-C₂₀ alkyl group, a fluorinated C₃-C₁₀         cycloalkyl group, a fluorinated C₂-C₁₀ heterocycloalkyl group,         or a fluorinated phenyl group, each unsubstituted or substituted         with deuterium, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group,         a C₂-C₁₀ heterocycloalkyl group, a phenyl group, or any         combination thereof.

In one or more embodiments, at least one of A₁ to A₅ in Formula 1 may each independently be a substituted or unsubstituted C₂-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In one or more embodiments, at least one of A₁ to A₆ in Formula 1 may each independently be a substituted or unsubstituted C₂-C₆₀ alkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, or a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group.

In one or more embodiments, at least one of A₁ to A₃ and at least one of A₄ to A₆ in Formula 1 may each independently be a substituted or unsubstituted C₂-C₆₀ alkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, or a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group.

In one or more embodiments, at least one of A₁ to A₆ in Formula 1 may each independently be a C₂-C₆₀ alkyl group, a C₃-C₁₀ cycloalkyl group, or a C₂-C₁₀ heterocycloalkyl group, each unsubstituted or substituted with deuterium, —F, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or any combination thereof.

In one or more embodiments, A₁ to A₆ in Formula 1 may each independently be a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In one or more embodiments, A₁ to A₆ in Formula 1 may each independently be a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, or a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group.

In one or more embodiments, A₁ to A₅ in Formula 1 may each independently be a C₁-C₆₀ alkyl group, a C₃-C₁₀ cycloalkyl group, or a C₂-C₁₀ heterocycloalkyl group, each unsubstituted or substituted with deuterium, —F, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or any combination thereof.

In one or more embodiments, A₇ in Formula 1 may be hydrogen or deuterium.

In one or more embodiments, A₇ in Formula 1 may not be hydrogen.

In one or more embodiments, A₇ in Formula 1 may be a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, or a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group.

In one or more embodiments, A₇ in Formula 1 may be a C₁-C₆₀ alkyl group, a C₃-C₁₀ cycloalkyl group, or a C₂-C₁₀ heterocycloalkyl group, each unsubstituted or substituted with deuterium, —F, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or any combination thereof.

For example, R₁ to R₈, A₂₀ and A₁ to A₇ in Formula 1 may each independently be hydrogen, deuterium, —F, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a group represented by one of Formulae 9-1 to 9-39, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 9-201 to 9-233, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-1 to 10-126, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-201 to 10-343, a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with —F, —Si(Q₃)(Q₄)(Q₅), or —Ge(Q₃)(Q₄)(Q₅) (herein Q₃ to Q₅ are the same as described in the present specification), and at least one of R₁ to R₈ (for example, at least one of R₂ to R₈, or at least one of R₃ to R₆) may be —F, —CF₃, —CF₂H, —CFH₂, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with —F, or a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with —F.

In one or more embodiments, A₂₀ in Formula 1 may be hydrogen, deuterium, —CH₃, —CD₃, —CD₂H, —CDH₂, a group represented by one of Formulae 9-1 to 9-39, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-201 to 9-233, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-126, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-201 to 10-343, a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with deuterium, —Si(Q₃)(Q₄)(Q₅), or —Ge(Q₃)(Q₄)(Q₅) (herein Q₃ to Q₅ are the same as described in the present specification).

In one or more embodiments, at least one of A₁ to A₆ in Formula 1 may each independently be a group represented by one of Formulae 9-1 to 9-39, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 9-201 to 9-233, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-1 to 10-126, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-201 to 10-343, a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with deuterium, or a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with —F.

In one or more embodiments, A₁ to A₅ in Formula 1 may each independently be —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a group represented by one of Formulae 9-1 to 9-39, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 9-201 to 9-233, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-1 to 10-126, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-201 to 10-343, a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with deuterium, or a group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with —F:

* in Formulae 9-1 to 9-39, 9-201 to 9-233, 10-1 to 10-126, and 10-201 to 10-343 indicates a binding site to a neighboring atom, Ph is a phenyl group, TMS is a trimethylsilyl group, and TMG is a trimethylgermyl group.

The “group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium” and the “group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium” may each be, for example, a group represented by one of Formulae 9-501 to 9-514 and 9-601 to 9-635:

The “group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F” and the “group represented by one of Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F” may each be, for example, a group represented by one of Formulae 9-701 to 9-710:

The “group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with deuterium” and the “group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with deuterium” may each be, for example, a group represented by one of Formulae 10-501 to 10-553:

The “group represented by one of Formulae 10-1 to 10-126 in which at least one hydrogen is substituted with —F” and the “group represented by one of Formulae 10-201 to 10-343 in which at least one hydrogen is substituted with —F” may each be, for example, a group represented by one of Formulae 10-601 to 10-617:

In one or more embodiments, in Formula 1,

-   -   1) R₂ may include at least one fluoro group (—F);     -   2) R₃ may include at least one fluoro group (—F);     -   3) R₄ may include at least one fluoro group (—F);     -   4) R₅ may include at least one fluoro group (—F);     -   5) R₆ may include at least one fluoro group (—F);     -   6) R₇ may include at least one fluoro group (—F);     -   7) R₈ may include at least one fluoro group (—F);     -   8) R₄ and R₅ may each include at least one fluoro group (—F);     -   9) R₄ and R₆ may each include at least one fluoro group (—F);     -   10) R₅ and R₆ may each include at least one fluoro group (—F);     -   11) R₃ and R₄ may each include at least one fluoro group (—F);         or     -   12) R₃ and R₆ may each include at least one fluoro group (—F).

In one or more embodiments, regarding Formula 1,

-   -   one or two of R₁ to R₈ may each independently include at least         one fluoro group (—F), and     -   at least one of R₁ to R₈ i) may not include a fluoro group (—F),         and ii) may not be hydrogen.

In one or more embodiments, A₂₀ in Formula 1 may be a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, or a C₂-C₁₀ heterocycloalkyl group, each unsubstituted or substituted with deuterium, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or any combination thereof.

In one or more embodiments, A₂₀ in Formula 1 may be a C₁-C₂₀ alkyl group, unsubstituted or substituted with deuterium, a C₁-C₂₀ alkyl group, or any combination thereof.

In one or more embodiments, d2 in Formula 1 may be 2.

In one or more embodiments, A₂₀ in Formula 1 may be a C₁-C₂₀ alkyl group, unsubstituted or substituted with deuterium, a C₁-C₂₀ alkyl group, or any combination thereof, and d2 may be 2.

In one or more embodiments, the organometallic compound represented by Formula 1 may have at least one deuterium.

In one or more embodiments, at least one of R₁ to R₈ of Formula 1 may have at least one deuterium.

In one or more embodiments, at least one of R₂₀ in number of d2 may have at least one deuterium.

In one or more embodiments, at least one of R₂₀ in number of d2 may be a deuterium-containing C₁-C₂₀ alkyl group, a deuterium-containing C₃-C₁₀ cycloalkyl group, or a deuterium-containing C₂-C₁₀ heterocycloalkyl group, each unsubstituted or substituted with a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or any combination thereof.

In one or more embodiments, a group represented by

in Formula 1 may be a group represented by one of Formulae CY1 to CY108:

In Formulae CY1 to CY108,

-   -   T₂ to T₈ may each independently be:     -   a fluoro group (—F); or     -   a fluorinated C₁-C₂₀ alkyl group, a fluorinated C₃-C₁₀         cycloalkyl group, a fluorinated C₂-C₁₀ heterocycloalkyl group,         or a fluorinated phenyl group, each unsubstituted or substituted         with deuterium, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group,         a C₂-C₁₀ heterocycloalkyl group, a phenyl group, or any         combination thereof;     -   each of R₂ to R₈ are the same as described above, and R₂ to R₈         may not be hydrogen,     -   * indicates a binding site to Ir in Formula 1,     -   *″ indicates a binding site to a neighboring atom in Formula 1.

For example, R₂ to R₈ and R_(1a) in Formulae CY1 to CY108 may each independently be:

-   -   deuterium; or     -   a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀         heterocycloalkyl group, or a phenyl group, each unsubstituted or         substituted with deuterium, a C₁-C₂₀ alkyl group, a C₃-C₁₀         cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a phenyl         group, or any combination thereof.

In one or more embodiments, the group represented by

in Formula 1 may be a group represented by one of Formulae A(1) to A(7):

In Formulae A(1) to A(7),

-   -   Y₂ is C,     -   X₂₁ is O, S, N(R₂₅), C(R₂₅)(R₂₆), or Si(R₂₅)(R₂),     -   each of R₉ to R₁₂ and R₂₁ to R_(2e) are the same as described in         connection with A₂₀,     -   *′ indicates a binding site to Ir in Formula 1, and     -   *″ indicates a binding site to a neighboring atom in Formula 1.

For example, R₉ and R₁₁ in Formula A(1) may each independently be a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or a phenyl group, each unsubstituted or substituted with deuterium, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a phenyl group, or any combination thereof.

In one or more embodiments, R₉ and R₁₁ in Formula A(1) may each independently be a C₁-C₂₀ alkyl group, unsubstituted or substituted with deuterium, a C₁-C₂₀ alkyl group, or any combination thereof.

In one or more embodiments, R₁₀ and R₁₂ in Formula A(1) may each independently be hydrogen or deuterium.

In one or more embodiments, R₉ and R₁₁ in Formula A(1) may be identical to each other.

In one or more embodiments, R₉ and R₁₁ in Formula A(1) may be different from each other.

In one or more embodiments, R₉ and R₁₁ in Formula A(1) may be different from each other, and the number of carbon included in R₁₁ may be greater than the number of carbon included in R₉.

In one or more embodiments, i) at least one of R₉ to R₁₂ in Formula A(1), ii) R₁₁, R₁₂, one of R₂₁ to R₂₆, or any combination thereof in Formulae A(2) and A(3), iii) R₉, R₁₂, one of R₂₁ to R₂₆, or any combination thereof in Formulae A(4) and A(5), and iv) R₉, R₁₀, one of R₂₁ to R₂₈, or any combination thereof in Formulae A(6) and A(7), may each independently be a deuterium-containing C₁-C₂₀ alkyl group, a deuterium-containing C₃-C₁₀ cycloalkyl group, or a deuterium-containing C₂-C₁₀ heterocycloalkyl group, each unsubstituted or substituted with a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or any combination thereof.

In one or more embodiments, at least one of R₉ and R₁₁ in Formula A(1) (for example, R₉ and R₁, in Formula A(1)) may each independently be a deuterium-containing C₁-C₂₀ alkyl group, a deuterium-containing C₃-C₁₀ cycloalkyl group, or a deuterium-containing C₂-C₁₀ heterocycloalkyl group, each unsubstituted or substituted with a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or any combination thereof.

In one or more embodiments, the group represented by

in Formula 1 may be a group represented by Formula A(1) or A(5).

In one or more embodiments, the number of carbon included in the group represented by *—C(A₁)(A₂)(A₃) in Formula 1 may be 5 or more, and/or the number of carbon included in the group represented by *—C(A₄)(A₅)(A₆) in Formula 1 may be 5 or more.

In one or more embodiments, A₁, A₂, and A₅ of the group represented by *—C(A₁)(A₂)(A₃) in Formula 1 may be linked to each other to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a). That is, the group represented by *—C(A₁)(A₂)(A₃) in Formula 1 may be a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a) (for example, an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group (a norbornane group), a bicyclo[2.2.2]octane group, a cyclopentane group, a cyclohexane group, or a cyclohexene group, each unsubstituted or substituted with at least one R_(1a)).

In one or more embodiments, A₄, A₅, and A₆ of the group represented by *—C(A₄)(A₅)(A₆) in Formula 1 may be linked to each other to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a). That is, the group represented by *—C(A₄)(A₅)(A₆) in Formula 1 may be a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R₁, or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a) (for example, an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group (a norbornane group), a bicyclo[2.2.2]octane group, a cyclopentane group, a cyclohexane group, or a cyclohexene group, each unsubstituted or substituted with at least one R_(1a)).

In one or more embodiments, in Formula 1, a group represented by *—C(A₁)(A₂)(A₃) may be identical to a group represented by *—C(A₄)(A₅)(A₆).

In one or more embodiments, in Formula 1, a group represented by *—C(A₁)(A₂)(A₃) may be different from a group represented by *—C(A₄)(A₅)(A₆).

In one or more embodiments, the first compound may include at least one of Compounds 1 to 53:

The first compound may include an organometallic compound represented by Formula 1. In an organometallic compound represented by Formula 1, 1) ring CY₁₁ (see Formula 1′) is, as illustrated in Formula 1, a condensed cyclic group in which two benzene groups are condensed with one pyridine group, and 2) at least one of R₁ to R₈, A₂₀ includes at least one a fluoro group (—F). Accordingly, the transition dipole moment of the organometallic compounds may be increased, and the conjugation length of the organometallic compounds is relatively increased and structural rigidity thereof is increased, leading to a decrease in non-radiative transition. Thus, an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may have high external quantum efficiency (EQE), and thus, may have high luminescence efficiency.

In one or more embodiments, when at least one of A₁ to A₆ in Formula 1 is each independently be a substituted or unsubstituted C₂-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group (that is, when at least one of A₁ to A₆ in Formula 1 has two or more carbons), an electron donating capability of Ligand 2 (see Formula 1′) in Formula 1 may be improved, and thus, an interaction between Ligand 1 and Ligand 2 in Formula 1 may be enhanced. Thus, the organometallic compound represented by Formula 1 may have improved luminescent transition characteristics, improved optical orientation characteristics, and improved structural rigidity. Accordingly, an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may have high luminescence efficiency and a long lifespan.

In one or more embodiments, when A₁ to A₆ in Formula 1 are each independently a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₁₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group (that is, when A₁ to A₆ in Formula 1 each have one or more carbons), carbons bound to each A₁ to A₆ in Formula 1 as described above may not include an α-proton, and in this regard, the organometallic compound represented by Formula 1 may have a stable chemical structure with minimal occurrence of a side reaction before/after synthesis, and at the same time, an intermolecular interaction of the organometallic compound represented by Formula 1 may be minimized during the operation of an electronic device (for example, an organic light-emitting device) including the organometallic compound represented by Formula 1. Furthermore, an interaction between Ligand 1 and Ligand 2 in Formula 1 may be enhanced and thus, the organometallic compound represented by Formula 1 may have improved structural rigidity, a full width at half maximum (FWHM) in the photoluminescent spectrum or electroluminescent spectrum of the organometallic compound represented by Formula 1 may be reduced, and a vibronic state of the organometallic compound represented by Formula 1 may be reduced. Accordingly a non-radiative decay of the organometallic compound represented by Formula 1 can be reduced and thus an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may have high luminescence efficiency and long lifespan.

A method of synthesizing the first compound represented by Formula 1 may be apparent to one of ordinary skill in the art by referring to Synthesis Examples provided herein.

Description of Formula 2

In Formula 2, Ar₁ may be a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R₆₁ or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R₆₁,

-   -   in Formula 2, Ar₂ may be a π electron-depleted         nitrogen-containing C₁-C₆₀ cyclic group unsubstituted or         substituted with at least one R₆₂,     -   in Formula 2, Ar₅ may not be present or may be a single bond, a         C₅-C₆₀ carbocyclic group unsubstituted or substituted with at         least one R₆₅, or a C₁-C₆₀ heterocyclic group unsubstituted or         substituted with at least one R₆₅,     -   in Formula 2, n may be 1, 2, or 3, and when n is 1, Ar₅ may not         be present,     -   in Formula 2, a1 and a2 may each independently be an integer         from 0 to 5, and the sum of a1 and a2 may be 1 or greater,     -   in Formula 2, ring CY₂ and ring CY₃ may each independently be a         C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, and         ring CY₂ and ring CY₃ may optionally be bound to each other via         or a C₅-C₆₀ carbocyclic group unsubstituted or substituted with         at least one R₆₆ or a C₁-C₆₀ heterocyclic group unsubstituted or         substituted with at least one R₆₆.

As used herein, the term “a π electron-depleted nitrogen-containing C₁-C₆₀ cyclic group” is a cyclic group having 1 to 60 carbon atoms and at least one *—N═*′ as a ring-forming moiety. The examples of r electron-depleted nitrogen-containing C₁-C₆₀ cyclic group may include a) a first ring, b) a condensed ring in which at least first rings or c) a condensed ring in which at least one first ring and at least one second ring are condensed. The examples of the first ring and the second ring may be understood by referring the descriptions herein.

For example, the π electron-depleted nitrogen-containing C₁-C₆₀ cyclic group may be an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a benzonaphthofuran group, a benzonaphthothiophene group, an indolophenanthrene group, a benzofuranophenanthrene group, a benzothienophenanthrene group, or a pyridopyrazine group.

As used herein, the term “a r electron-rich C₃-C₆₀ cyclic group” is a cyclic group having 3 to 60 carbon atoms and not having *—N═*′ as a ring-forming moiety. The examples of π electron-rich C₃-C₆₀ cyclic group may include a) a second ring, or b) a condensed ring in which at least second rings. The examples of the second ring may be understood by referring the descriptions herein.

For example, the π electron-rich C₃-C₆₀ cyclic group may be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, a naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, an acridine group, a dihydroacridine group, a pyrrolophenanthrene group, a furanophenanthrene group, or a thienophenanthrene group.

In some embodiments,

-   -   Ar₁ in Formula 2 may be a group derived from i) a first ring         unsubstituted or substituted with at least one R₆₁, ii) a second         ring unsubstituted or substituted with at least one R₆₁, iii) a         condensed ring in which at least two first rings are condensed,         unsubstituted or substituted with at least one R₆₁, iv) a         condensed ring in which at least two second rings are condensed,         unsubstituted or substituted with at least one R₆₁, or v) a         condensed ring in which at least one first ring and at least one         second ring are condensed, unsubstituted or substituted with at         least one R₆₁,     -   Ar₂ in Formula 2 may be a group derived from i) a first ring         unsubstituted or substituted with at least one R₆₂, ii) a         condensed ring in which at least two first rings are condensed,         unsubstituted or substituted with at least one R₆₂, or iii) a         condensed ring in which at least one first ring and at least one         second ring are condensed, unsubstituted or substituted with at         least one R₆₂,     -   Ar₅ in Formula 2 may not be present or be a single bond or a         group derived from i) a first ring unsubstituted or substituted         with at least one R₆₅, ii) a second ring unsubstituted or         substituted with at least one R₆₅, iii) a condensed ring in         which at least two first rings are condensed, unsubstituted or         substituted with at least one R₆₅, iv) a condensed ring in which         at least two second rings are condensed, unsubstituted or         substituted with at least one R₆₅, or v) a condensed ring in         which at least one first ring and at least one second ring are         condensed, unsubstituted or substituted with at least one R₆₅,     -   ring CY₂ and ring CY₃ in Formula 2 may each independently be i)         a first ring, ii) a second ring, iii) a condensed ring in which         at least two first rings are condensed, iv) a condensed ring in         which at least two second rings are condensed, or v) a condensed         ring in which at least one first ring and at least one second         ring are condensed,     -   the first ring may be an imidazole group, a pyrazole group, a         thiazole group, an isothiazole group, an oxazole group, an         isoxazole group, a pyridine group, a pyrazine group, a         pyridazine group, a pyrimidine group, a triazole group, a         tetrazole group, an oxadiazole group, a triazine group, or a         thiadiazole group, and     -   the second ring may be a benzene group, a cyclopentadiene group,         a pyrrole group, a furan group, a thiophene group, or a silole         group.

In one or more embodiments, in Formula 2, Ar₁ may be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, a naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, an acridine group, a dihydroacridine group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, or an azadibenzosilole group, each unsubstituted or substituted with at least one R₆₁.

In one or more embodiments, Ar₂ in Formula 2 may be an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, or a pyridopyrazine group, each unsubstituted or substituted with at least one R₆₂.

In one or more embodiments, ring CY₂ and ring CY₃ may each independently be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, a naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, an acridine group, a dihydroacridine group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, or an azadibenzosilole group.

In one or more embodiments, in Formula 2, when n is 1, at least one of the ring CY₂ and the ring CY₃ may not be a benzene group.

In one or more embodiments, ring CY₂ and ring CY₃ in Formula 2 may each independently be a π electron-rich C₃-C₆₀ cyclic group.

In one or more embodiments, in Formula 2, when n is 1, at least one of the ring CY₂ and the ring CY₃ may be a) a condensed ring in which at least two first rings are condensed, b) a condensed ring in which at least two second rings are condensed, or c) a condensed ring in which at least one first ring and at least one second ring are condensed. The examples of the first ring and the second ring may be understood by referring the descriptions herein.

In one or more embodiments, the second compound may include a compound represented by Formula 2(1):

wherein, in Formula 2(1),

-   -   Ar₅ may be a single bond, a C₅-C₆₀ carbocyclic group         unsubstituted or substituted with at least one R₆₅, or a C₁-C₆₀         heterocyclic group unsubstituted or substituted with at least         one R₆₅,     -   Ar₁, Ar₂, Ar₅, a1, a2, ring CY2, ring CY₃, R₂₀, R₃₀, b2, and b3         are respectively understood by referring to the descriptions of         Ar₁, Ar₂, Ar₅, a1, a2, ring CY₂, ring CY₃, R₂₀, R₃₀, b2, and b3         provided herein,     -   Ar₃ and Ar₄ are each understood by referring to the descriptions         of Ar₁ provided herein, and     -   a3, a4, ring CY4, ring CY5, R₄₀, R₅₀, b4, and b5 are         respectively understood by referring to the descriptions of a1,         a2, ring CY₂, ring CY₃, R₂₀, R₃₀, b2, and b3 provided herein.

For example, Ar₅ in Formula 2(1) may be a single bond.

In one or more embodiments, a group represented by

in Formulae 2 and 2(1) and a group represented by

in Formula 2(1) may each independently be a group represented by one of Formulae 2-1 to 2-93:

wherein, in Formulae 2-1 to 2-93,

-   -   X₁ may be O, S, N(R₃₁), C(R₃₁)(R₃₂), or Si(R₃₁)(R₃₂),     -   X₂ may be O, S, N(R₃₃), C(R₃₃)(R₃₄), or Si(R₃₃)(R₄),     -   R₃₁ to R₃₄ may each be understood by referring to the         description of R₃₀ provided herein, and     -   * in Formula 2 indicates a binding site to Ar₁ or Ar₂.

In some embodiments, in Formulae 2 and 2(1), Ar₂ may be a group represented by one of Formulae 5-1 to 5-31:

wherein, in Formulae 5-1 to 5-31,

-   -   R₆₂ may be understood by referring to the description of R₆₂         provided herein,     -   c2 may be an integer from 0 to 2,     -   c3 may be an integer from 0 to 3,     -   c4 may be an integer from 0 to 4,     -   c5 may be an integer from 0 to 5,     -   c7 may be an integer from 0 to 7, and     -   * indicates a binding site to Ar₁ or N in Formulae 2 and 2(1).

In Formulae 2 and 2(1), a1 and a2 each indicate the number of Ar₁(s) and Ar₂(s), respectively. a1 and a2 may each independently be an integer from 0 to 5, and the sum of a1 and a2 may be 1 or greater. When all is two or greater, at least two Ar₁ groups may be identical to or different from each other, and when a2 is two or greater, at least two Ar₂ groups may be identical to or different from each other. When a1 is 0, in Formula 2, *—(Ar₁)_(a1)—*′ may be a single bond.

In some embodiments, in Formulae 2 and 2(1), a2 may not be 0.

In some embodiments, in Formulae 2 and 2(1), a2 may be 1 or 2.

In one or more embodiments, in Formulae 2 and 2(1), a2 may be 1 or 2 and Ar₃ and Ar₄ may each independently be a π electron-rich C₃-C₆₀ cyclic group (for example, a benzene group, a naphthalene group, a phenanthrene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, etc.) unsubstituted or substituted with deuterium, a C₁-C₂₀ alkyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, or any combination thereof.

In one or more embodiments, in Formula 2, n may be 1 or 2.

In Formula 2, R₂₀, R₃₀, R₆₁, R₆₂, R₆₅, and R₆₆ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₆₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉). Q₁ to Q₉ may respectively be understood by referring to the descriptions of Q₁ to Q₉ provided herein.

In some embodiments, in Formula 2, R₂₀, R₃₀, R₆₁, R₆₂, R₆₅, and R₆₆ may each independently be:

-   -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid or a salt         thereof, a sulfonic acid or a salt thereof, a phosphoric acid or         a salt thereof, —SF₅, a C₁-C₂₀ alkyl group, or a C₁-C₂₀ alkoxy         group;     -   a C₁-C₂₀ alkyl group or a C₁-C₂₀ alkoxy group, each substituted         with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,         —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an         amino group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a C₁-C₂₀ alkyl group, a deuterium-containing C₁-C₂₀         alkyl group, a fluorinated C₁-C₂₀ alkyl group, a cyclopentyl         group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl         group, an adamantyl group, a norbomenyl group, a cyclopentenyl         group, a cyclohexenyl group, a cycloheptenyl group, a         bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a         bicyclo[2.2.1]heptyl group (a norbornanyl group), a         bicyclo[2.2.2]octyl group, a (C₁-C₂₀ alkyl)cyclopentyl group, a         (C₁-C₂₀ alkyl)cyclohexyl group, a (C₁-C₂₀ alkyl)cycloheptyl         group, a (C₁-C₂₀ alkyl)cyclooctyl group, a (C₁-C₂₀         alkyl)adamantyl group, a (C₁-C₂₀ alkyl)norbomenyl group, a         (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀ alkyl)cyclohexenyl         group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a (C₁-C₂₀         alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.1]heptyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a silolanyl group, a phenyl         group, a (C₁-C₂₀ alkyl)phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, a 1,2,3,4-tetrahydronaphthyl         group, a pyridinyl group, a pyrimidinyl group, or any         combination thereof;     -   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantyl group, a norbornenyl group, a         cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl         group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl         group, a bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl         group, a silolanyl group, a phenyl group, a (C₁-C₂₀ alkyl)phenyl         group, a biphenyl group, a terphenyl group, a naphthyl group, a         1,2,3,4-tetrahydronaphthyl group, a fluorenyl group, a         phenanthrenyl group, an anthracenyl group, a fluoranthenyl         group, a triphenylenyl group, a pyrenyl group, a chrysenyl         group, a pyrrolyl group, a thiophenyl group, a furanyl group, an         imidazolyl group, a pyrazolyl group, a thiazolyl group, an         isothiazolyl group, an oxazolyl group, an isoxazolyl group, a         pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a         pyridazinyl group, an isoindolyl group, an indolyl group, an         indazolyl group, a purinyl group, a quinolinyl group, an         isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl         group, a quinazolinyl group, a cinnolinyl group, a carbazolyl         group, a phenanthrolinyl group, a benzimidazolyl group, a         benzofuranyl group, a benzothiophenyl group, an         isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, an imidazopyridinyl group, an         imidazopyrimidinyl group, an azacarbazolyl group, an         azadibenzofuranyl group, or an azadibenzothiophenyl group, each         unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I,         —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a         cyano group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a         deuterium-containing C₁-C₂₀ alkyl group, a fluorinated C₁-C₂₀         alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a         cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an         adamantyl group, a norbomenyl group, a cyclopentenyl group, a         cyclohexenyl group, a cycloheptenyl group, a         bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a         bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantyl group, a         (C₁-C₂₀ alkyl)norbomenyl group, a (C₁-C₂₀ alkyl)cyclopentenyl         group, a (C₁-C₂₀ alkyl)cyclohexenyl group, a (C₁-C₂₀         alkyl)cycloheptenyl group, a (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl         group, a (C₁-C₂₀ alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.1]heptyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a silolanyl group, a phenyl         group, a (C₁-C₂₀ alkyl)phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, a 1,2,3,4-tetrahydronaphthyl         group, a fluorenyl group, a phenanthrenyl group, an anthracenyl         group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl         group, a chrysenyl group, a pyrrolyl group, a thiophenyl group,         a furanyl group, an imidazolyl group, a pyrazolyl group, a         thiazolyl group, an isothiazolyl group, an oxazolyl group, an         isoxazolyl group, a pyridinyl group, a pyrazinyl group, a         pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an         indolyl group, an indazolyl group, a purinyl group, a quinolinyl         group, an isoquinolinyl group, a benzoquinolinyl group, a         quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a         carbazolyl group, a phenanthrolinyl group, a benzimidazolyl         group, a benzofuranyl group, a benzothiophenyl group, an         isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, an imidazopyridinyl group, an         imidazopyrimidinyl group, an azacarbazolyl group, an         azadibenzofuranyl group, an azadibenzothiophenyl group, or any         combination thereof; or     -   —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇),         —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉),     -   Q₁ to Q₆ may each independently be:     -   —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂,         —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H or         —CD₂CDH₂; or         an n-propyl group, an isopropyl group, an n-butyl group, a         sec-butyl group, an isobutyl group, a tert-butyl group, an         n-pentyl group, a tert-pentyl group, a neopentyl group, an         isopentyl group, a sec-pentyl group, a 3-pentyl group, a         sec-isopentyl group, a phenyl group, a biphenyl group, or a         naphthyl group, each unsubstituted or substituted with         deuterium, a C₁-C₂₀ alkyl group, a phenyl group, or any         combination thereof.

In Formula 2, b2 and b3 may each indicate the number of R₂₀(s) and R₃₀(s), respectively. b2 and b3 may each independently be an integer from 0 to 20. In some embodiments, b2 and b3 may each independently be an integer from 0 to 10. When b2 is two or greater, at least two R₂₀(s) may be identical to or different from each other, and when b3 is two or greater, at least two R₃₀(s) may be identical to or different from each other.

In one or more embodiments, R₂₀, R₃₀, R₆₁, R₆₂, R₆₅, and R₆₆ in Formulae 2 and 3 may each independently be:

-   -   hydrogen or deuterium;     -   a C₁-C₂₀ alkyl group or a C₁-C₂₀ alkoxy group, each         unsubstituted or substituted with deuterium, a phenyl group, a         naphthyl group, an anthracenyl group, a phenanthrenyl group, a         triphenylenyl group, a fluorenyl group, a di(C₁-C₁₀         alkyl)fluorenyl group, a di(C₆-C₆₀ aryl)fluorenyl group, a         dibenzosilolyl group, a di(C₁-C₁₀ alkyl)dibenzosilolyl group, a         di(C₆-C₆₀ aryl)dibenzosilolyl group, a carbazolyl group, a         (C₁-C₁₀ alkyl)carbazolyl group, a (C₆-C₆₀ aryl)carbazolyl group,         a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl         group, a terphenyl group, —N(Q₃₁)(Q₃₂), or any combination         thereof;     -   a π electron-rich C₃-C₆₀ cyclic group, unsubstituted or         substituted with deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀         alkoxy group, a phenyl group, a naphthyl group, an anthracenyl         group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl         group, a di(C₁-C₁₀ alkyl)fluorenyl group, a di(C₆-C₆₀         aryl)fluorenyl group, a dibenzosilolyl group, a di(C₁-C₁₀         alkyl)dibenzosilolyl group, a di(C₆-C₆₀ aryl)dibenzosilolyl         group, a carbazolyl group, a (C₁-C₁₀ alkyl)carbazolyl group, a         (C₆-C₆₀ aryl)carbazolyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a biphenyl group, a terphenyl group,         —N(Q₃₁)(Q₃₂), or any combination thereof; or     -   —N(Q₁)(Q₂). Herein, Q₁, Q₂, Q₃₁ and Q₃₂ are each independently         the same as described herein.

In one or more embodiments, R₂₀, R₃₀, R₆₁, R₆₂, R₆₅, and R₆₆ in Formulae 2 and 3 may each independently be:

-   -   hydrogen or deuterium;     -   a C₁-C₂₀ alkyl group unsubstituted or substituted with         deuterium, a phenyl group, a naphthyl group, an anthracenyl         group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl         group, a di(C₁-C₁₀ alkyl)fluorenyl group, a di(C₆-C₆₀         aryl)fluorenyl group, a dibenzosilolyl group, a di(C₁-C₁₀         alkyl)dibenzosilolyl group, a di(C₆-C₆₀ aryl)dibenzosilolyl         group, a carbazolyl group, a (C₁-C₁₀ alkyl)carbazolyl group, a         (C₆-C₆₀ aryl)carbazolyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a biphenyl group, a terphenyl group,         —N(Q₃₁)(Q₃₂), or any combination thereof; or     -   a phenyl group, a naphthyl group, an anthracenyl group, a         phenanthrenyl group, a triphenylenyl group, a fluorenyl group, a         dibenzosilolyl group, a carbazolyl group, a dibenzofuranyl         group, or a dibenzothiophenyl group, unsubstituted or         substituted with deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀         alkoxy group, a phenyl group, a naphthyl group, an anthracenyl         group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl         group, a di(C₁-C₁₀ alkyl)fluorenyl group, a di(C₆-C₆₀         aryl)fluorenyl group, a dibenzosilolyl group, a di(C₁-C₁₀         alkyl)dibenzosilolyl group, a di(C₆-C₆₀ aryl)dibenzosilolyl         group, a carbazolyl group, a (C₁-C₁₀ alkyl)carbazolyl group, a         (C₆-C₆₀ aryl)carbazolyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a biphenyl group, a terphenyl group,         —N(Q₃₁)(Q₃₂), or any combination thereof. Herein, Q₃₁ and Q₃₂         are each independently the same as described herein.

In some embodiments, the second compound represented by Formula 2 may include at least one of Compounds H1 to H90, but embodiments are not limited thereto:

An electronic device, for example, an organic light-emitting device, including the second may have high external quantum efficiency (EQE) and long lifespan.

In Formulae 1 and 2, 1) two or more of R₁ to R₈ and A₂₀ may be optionally linked to each other to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a), 2) two or more of A₁ to A₇ may be optionally linked to each other to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a) and 3) two or more of ring CY2, ring CY₃, R₂₀ and R₃₀ may be optionally linked to each other to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a). Herein, R_(1a) may be understood by referring to the description of A_(T).

The term “C₅-C₆₀ carbocyclic group” as used herein refers to a saturated or unsaturated cyclic group including 5 to 60 carbon atoms only as ring-forming atoms. The C₅-C₆₀ carbocyclic group may be a monocyclic group or a polycyclic group.

The phrase “a C₅-C₆₀ carbocyclic group (which is unsubstituted or substituted with at least one R_(1a))” may include, for example, an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group (a norbornane group), a bicyclo[2.2.2]octane group, a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, cyclopentadiene group, a fluorene group, and a 1,2,3,4-tetrahydronaphthalene group, each being unsubstituted or substituted with at least one R_(1a).

The term “C₁-C₆₀ heterocyclic group” as used herein refers to saturated or unsaturated cyclic group including 1 to 60 carbon atoms and at least one heteroatom selected from N, O, P, Si, and S as ring-forming atoms. The C₁-C₆₀ heterocyclic group may be a monocyclic group or a polycyclic group.

The phrase “a C₁-C₆₀ heterocyclic group (which is unsubstituted or substituted with at least one R_(1a))” may include a thiophene group, a furan group, a pyrrole group, a silole group, a borole group, a phosphole group, a selenophene group, a germole group, a benzothiophene group, a benzofuran group, an indole group, an indene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzoselenophene group, a benzogermole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzoselenophene group, a dibenzogermole group, a dibenzothiophene 5-oxide group, 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azabenzothiophene group, an azabenzofuran group, an azaindole group, an azaindene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzoselenophene group, an azabenzogermole group, an azadibenzothiophene group, an azadibenzofuran group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzoselenophene group, an azadibenzogermole group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isooxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, each being unsubstituted or substituted with at least one R_(1a).

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms. The term “C₁-C₆₀ alkylene group” as used herein refers to a divalent group having substantially the same structure as the C₁-C₆₀ alkyl group.

Examples of the C₁-C₆₀ alkyl group, the C₁-C₂₀ alkyl group, and/or the C₁-C₁₀ alkyl group are a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, and a tert-decyl group, each unsubstituted or substituted with a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, a tert-decyl group, or any combination thereof. For example, Formula 9-33 may be a branched C₆ alkyl group, and may be a tert-butyl group that is substituted with two methyl groups.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is a C₁-C₆₀ alkyl group). Examples of the C₁-C₆₀ alkoxy group, the C₁-C₂₀ alkoxy group, or the C₁-C₁₀ alkoxy group are a methoxy group, an ethoxy group, a propoxy group, a butoxy group, or a pentoxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalent monocyclic saturated hydrocarbon group including 3 to 10 carbon atoms. The term “C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent group having substantially the same structure as the C₃-C₁₀ cycloalkyl group.

Examples of the C₃-C₁₀ cycloalkyl group are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantyl group, a bicyclo[1.1.1]pentyl group (bicyclo[1.1.1]pentyl), a bicyclo[2.1.1]hexyl group (bicyclo[2.1.1]hexyl), a bicyclo[2.2.1]heptyl group (bicyclo[2.2.1]heptyl)(a norbornanyl group), and a bicyclo[2.2.2]octyl group.

The term “C₂-C₁₀ heterocycloalkyl group” as used herein refers to a monovalent saturated monocyclic group having at least one heteroatom selected from N, O, P, Si Se, B, Ge, or S as a ring-forming atom and 2 to 10 carbon atoms, and non-limiting examples thereof include a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₂-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C₂-C₁₀ heterocycloalkyl group.

Examples of the C₂-C₁₀ heterocycloalkyl group are a silolanyl group, a silinanyl group, a tetrahydrofuranyl group, a tetrahydro-2H-pyranyl group, and a tetrahydrothiophenyl group.

The term “deuterium-containing C₁-C₆₀ alkyl group (or, deuterium-containing C₁-C₂₀ alkyl group, a deuterium-containing C₂-C₂₀ alkyl group, or the like)” as used herein refers to a C₁-C₆₀ alkyl group substituted with at least one deuterium (or a C₁-C₂₀ alkyl group substituted with at least one deuterium, a C₂-C₂₀ alkyl substituted with at least one deuterium, or the like). For example, the term “the deuterium-containing C, alkyl group (that is, a deuterium-containing methyl group)” as used herein includes —CD₃, —CD₂H, and —CDH₂.

The term “deuterium-containing C₃-C₁₀ cycloalkyl group” as used herein refers to a C₃-C₁₀ cycloalkyl group substituted with at least one deuterium. Examples of the “deuterium-containing C₃-C₁₀ cycloalkyl group” are provided in connection with, for example, Formula 10-501.

The terms “fluorinated C₁-C₆₀ alkyl group (or a fluorinated C₁-C₂₀ alkyl group, or the like)”, “fluorinated C₃-C₁₀ cycloalkyl group”, “fluorinated C₂-C₁₀ heterocycloalkyl group” or “fluorinated phenyl group” as used herein refer to a C₁-C₆₀ alkyl group (or, C₁-C₂₀ alkyl group, or the like) substituted with at least one a fluoro group (—F), a C₃-C₁₀ cycloalkyl group substituted with at least one a fluoro group (—F), a C₂-C₁₀ heterocycloalkyl group substituted with at least one a fluoro group (—F), and a phenyl group substituted with at least one a fluoro group (—F), respectively. For example, the term “the fluorinated C, alkyl group (that is, the fluorinated methyl group)” includes —CF₃, —CF₂H, and —CFH₂. The “fluorinated C₁-C₆₀ alkyl group (or the fluorinated C₁-C₂₀ alkyl group, or the like)”, “the fluorinated C₃-C₁₀ cycloalkyl group”, or “the fluorinated C₂-C₁₀ heterocycloalkyl group” may be i) a fully fluorinated C₁-C₆₀ alkyl group (or, fully fluorinated C₁-C₂₀ alkyl group, or the like), a fully fluorinated C₃-C₁₀ cycloalkyl group, or a fully fluorinated C₂-C₁₀ heterocycloalkyl group, each group in which all hydrogen are substituted with a fluoro group, or ii) a partially fluorinated C₁-C₁₀ alkyl group (or, a partially fluorinated C₁-C₂₀ alkyl group, or the like), a partially fluorinated C₃-C₁₀ cycloalkyl group, or a partially fluorinated C₂-C₁₀ heterocycloalkyl group, each group in which some hydrogen are substituted with a fluoro group.

The term “(C₁-C₂ alkyl)‘X’ group” as used herein refers to a ‘X’ group substituted with at least one C₁-C₂₀ alkyl group. For example, the term “(C₁-C₂₀ alkyl)C₃-C₁₀ cycloalkyl group” as used herein refers to a C₃-C₁₀ cycloalkyl group substituted with at least one C₁-C₂₀ alkyl group and the term “(C₁-C₂₀ alkyl)phenyl group” as used herein refers to a phenyl group substituted with at least one C₁-C₂₀ alkyl group.

The terms “an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, and an azadibenzothiophene 5,5-dioxide group” respectively refer to a heterocyclic group having the same backbone as “an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene 5-oxide group, 9H-fluorene-9-one group, and a dibenzothiophene 5,5-dioxide group” in which at least one carbon atoms constituting the cyclic groups is substituted with a nitrogen.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a group formed by including at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀ alkyl group. Examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a group formed by including at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀ alkyl group. Examples thereof include an ethenyl group and a propenyl group. The term “C₂-C₆₀ alkynylene group” as used herein refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to a monovalent monocyclic group including 3 to 10 carbon atoms and at least one carbon-carbon double bond in its ring, wherein the molecular structure as a whole is non-aromatic. Examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers to a divalent group having substantially the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₂-C₁₀ heterocycloalkenyl group” as used herein refers to a monovalent monocyclic group including at least one heteroatom selected from N, O, P, Si, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Examples of the C₂-C₁₀ heterocycloalkenyl group include a 2,3-dihydrofuranyl group and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having substantially the same structure as the C₂-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent group having a carbocylic aromatic system having 6 to 60 carbon atoms. The term “C₆-C₆₀ arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and a C₆-C₆₀ arylene group each include at least two rings, the at least two rings may be fused.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system having at least one heteroatom selected from N, O, P, Si, and S as a ring-forming atom and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system having at least one heteroatom selected from N, O, P, and S as a ring-forming atom and 1 to 60 carbon atoms. Examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include at least two rings, the at least two rings may be fused.

The term “C₆-C₆₀ aryloxy group” as used herein indicates —OA₁₀₂ (wherein A₁₀₂ is a C₆-C₆₀ aryl group). The term “C₆-C₆₀ arylthio group” as used herein indicates —SA₁₀₃ (wherein A₁₀₃ is a C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group that has two or more condensed rings and only carbon atoms (e.g., the number of carbon atoms may be in a range of 8 to 60) as ring-forming atoms, wherein the molecular structure as a whole is non-aromatic. Examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group that has two or more condensed rings and a heteroatom selected from N, O, P, Si, and S and carbon atoms (e.g., the number of carbon atoms may be in a range of 1 to 60) as ring-forming atoms, wherein the molecular structure as a whole is non-aromatic. Examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₁-C₆₀ cyclic group” includes the C₅-C₆₀ carbocyclic group and the C₁-C₆₀ heterocyclic group.

A substituent of the substituted C₅-C₆₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be:

-   -   deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an         amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, or a C₁-C₆₀ alkoxy group;     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, or a C₁-C₆₀ alkoxy group, each unsubstituted or         substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H,         —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl         group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl         group, a C₆-C₆₀ aryl group, a C₇-C₆₀ alkyl aryl group, a C₆-C₆₀         aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl         group, a C₂-C₆₀ alkyl heteroaryl group, a monovalent         non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂),         —Si(Q₁₃)(Q₁₄)(Q₁₅), —Ge(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇),         —P(═O)(Q₁₈)(Q₁₉), —P(Q₁₈)(Q₁₉), or any combination thereof;     -   a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₇-C₆₀ alkylaryl group, a C₆-C₆₀ aryloxy         group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a         C₂-C₆₀ alkyl heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, or a monovalent non-aromatic         condensed heteropolycyclic group, each unsubstituted or         substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H,         —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀         alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,         a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a         C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₇-C₆₀         alkylaryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a C₂-C₆₀ alkyl heteroaryl         group, a monovalent non-aromatic condensed polycyclic group, a         monovalent non-aromatic condensed heteropolycyclic group,         —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —Ge(Q₂₃)(Q₂₄)(Q₂₅),         —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉), —P(Q₂₈)(Q₂₉), or any combination         thereof;     -   —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —Ge(Q₃₃)(Q₃₄)(Q₃₅),         —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉), or —P(Q₃₈)(Q₃₉); or     -   any combination thereof.

In the present specification, Q₁ to Q₆, Q₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently be hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group, unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₂-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₂-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group, unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₅-C₆₀ aryl group, or any combination thereof; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed polycyclic group; or a monovalent non-aromatic condensed heteropolycyclic group.

For example, in the present specification, Q₁ to Q₆, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently be

-   -   —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂,         —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, or         —CD₂CDH₂; or     -   an n-propyl group, an isopropyl group, an n-butyl group, a         sec-butyl group, an isobutyl group, a tert-butyl group, an         n-pentyl group, a tert-pentyl group, a neopentyl group, an         isopentyl group, a sec-pentyl group, a 3-pentyl group, a         sec-isopentyl group, a phenyl group, a biphenyl group, or a         naphthyl group, each unsubstituted or substituted with         deuterium, a C₁-C₁₀ alkyl group, a phenyl group, or any         combination thereof.

Thus, a composition including the first compound and the second compound may be suitable for use in an organic layer of an organic light-emitting device, e.g., as an emission layer material in the organic layer. Therefore, according to another aspect, an organic light-emitting device may include a first electrode; a second electrode; and an organic layer disposed between the first electrode and the second electrode and including an emission layer, wherein the organic layer includes the composition.

Since the organic light-emitting device includes the composition including the first and second compounds, the organic light-emitting device may have a low driving voltage, high external quantum efficiency, and long lifespan.

The composition may be used in a pair of electrodes of an organic light-emitting device. In some embodiments, the composition may be included in the emission layer. In this embodiment, the first compound may serve as a dopant, and the second compound may serve as a host. For example, a content of the second compound may be greater than a content of the first compound. The emission layer may emit red light, e.g., red light having a maximum emission wavelength of 550 nanometers (nm) or longer (e.g., about 550 nm to about 900 nm).

The first electrode may be an anode, which is a hole injection electrode, and the second electrode may be a cathode, which is an electron injection electrode. In some embodiments, the first electrode may be a cathode, which is an electron injection electrode, and the second electrode may be an anode, which is a hole injection electrode.

For example, in the organic light-emitting device, the first electrode may be an anode, the second electrode may be a cathode, and the organic layer may further include a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode, wherein the hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof, and the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

The term “organic layer” as used herein refers to a single and/or a plurality of layers between the first electrode and the second electrode in an organic light-emitting device. The “organic layer” may include not only organic compounds but also organometallic complexes including metals.

The FIGURE illustrates a schematic cross-sectional view of an organic light-emitting device 10 according to an embodiment. Hereinafter, a structure of an organic light-emitting device according to one or more embodiments and a method of manufacturing the organic light-emitting device will be described with reference to the FIGURE. The organic light-emitting device 10 may include a first electrode 11, an organic layer 15, and a second electrode 19, which may be sequentially layered in this stated order.

A substrate may be additionally disposed under the first electrode 11 or on the second electrode 19. The substrate may be a conventional substrate used in organic light-emitting devices, e.g., a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water repellency.

The first electrode 11 may be formed by depositing or sputtering, onto the substrate, a material for forming the first electrode 11. The first electrode 11 may be an anode. The material for forming the first electrode 11 may be selected from materials with a high work function for easy hole injection. The first electrode 11 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. The material for forming the first electrode 11 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), and zinc oxide (ZnO). In some embodiments, the material for forming the first electrode 11 may be a metal, such as magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

The first electrode 11 may have a single-layered structure or a multi-layered structure including a plurality of layers. In some embodiments, the first electrode 11 may have a triple-layered structure of ITO/Ag/ITO, but embodiments are not limited thereto.

The organic layer 15 may be on the first electrode 11.

The organic layer 15 may include a hole transport region, an emission layer, and an electron transport region.

The hole transport region may be between the first electrode 11 and the emission layer.

The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof.

The hole transport region may include a hole injection layer only or a hole transport layer only. In some embodiments, the hole transport region may include a hole injection layer and a hole transport layer which are sequentially stacked on the first electrode 11. In some embodiments, the hole transport region may include a hole injection layer, a hole transport layer, and an electron blocking layer, which are sequentially stacked on the first electrode 11.

When the hole transport region includes a hole injection layer, the hole injection layer may be formed on the first electrode 11 by using one or more suitable methods, such as vacuum deposition, spin coating, casting, and Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum-deposition, for example, the vacuum deposition may be performed at a temperature in a range of about 100° C. to about 500° C., at a vacuum pressure in a range of about 10⁻⁸ torr to about 10⁻³ torr, and at a rate in a range of about 0.01 Angstroms per second (A/sec) to about 100 Å/sec, though the conditions may vary depending on a compound used as a hole injection material and a structure and thermal properties of a desired hole injection layer, but embodiments are not limited thereto.

When a hole injection layer is formed by spin coating, the spin coating may be performed at a rate in a range of about 2,000 revolutions per minute (rpm) to about 5,000 rpm and at a temperature in a range of about 80° C. to 200° C. to facilitate removal of a solvent after the spin coating, though the conditions may vary depending on a compound used as a hole injection material and a structure and thermal properties of a desired hole injection layer, but embodiments are not limited thereto.

The conditions for forming a hole transport layer and an electron blocking layer may be inferred from the conditions for forming the hole injection layer.

The hole transport region may include m-MTDATA, TDATA, 2-TNATA, NPB, 3-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor-sulfonic acid (PANI/CSA), polyaniline)/poly(4-styrenesulfonate (PANI/PSS), a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:

Ar₁₀₁ and Ar₁₀₂ in Formula 201 may each independently be a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, or a pentacenylene group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, or any combination thereof.

The designations xa and xb in Formula 201 may each independently be an integer from 0 to 5, or 0, 1 or 2. For example, xa may be 1 and xb may be 0, but xa and xb are not limited thereto.

R₁₀₁ to R₁₀, R₁₁₁ to R₁₁₉ and R₁₂₁ to R₁₂₄ in Formulae 201 and 202 may each independently be:

-   -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid or a salt         thereof, a sulfonic acid or a salt thereof, a phosphoric acid or         a salt thereof, a C₁-C₁₀ alkyl group (for example, a methyl         group, an ethyl group, a propyl group, a butyl group, a pentyl         group, or a hexyl group), or a C₁-C₁₀ alkoxy group (for example,         a methoxy group, an ethoxy group, a propoxy group, a butoxy         group, or a pentoxy group);     -   a C₁-C₁₀ alkyl group or a C₁-C₁₀ alkoxy group, each         unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a         hydroxyl group, a cyano group, a nitro group, an amino group, an         amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, or         any combination thereof; or     -   a phenyl group, a naphthyl group, an anthracenyl group, a         fluorenyl group, or a pyrenyl group, each unsubstituted or         substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amino group, an amidino group,         a hydrazine group, a hydrazone group, a carboxylic acid or a         salt thereof, a sulfonic acid or a salt thereof, a phosphoric         acid or a salt thereof, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy         group, or any combination thereof.

R₁₀ in Formula 201 may be a phenyl group, a naphthyl group, an anthracenyl group, or a pyridinyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a pyridinyl group, or any combination thereof.

In some embodiments, the compound represented by Formula 201 may be represented by Formula 201A:

wherein, in Formula 201A, R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ may respectively be understood by referring to the descriptions of R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ provided herein.

In some embodiments, the hole transport regions may include at least one of Compounds HT1 to HT20:

The thickness of the hole transport region may be in a range of about 100 Angstroms (Å) to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, the thickness of the hole injection layer may be in a range of about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å, the thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within any of these ranges, excellent hole transport characteristics may be obtained without a substantial increase in driving voltage.

The hole transport region may include a charge generating material as well as the aforementioned materials, to improve conductive properties of the hole transport region. The charge generating material may be substantially homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant. The p-dopant may be a quinone derivative, a metal oxide, a cyano group-containing compound, or any combination thereof, but embodiments of the present disclosure are not limited thereto. Examples of the p-dopant are a quinone derivative, such as tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethane (F4-TCNQ), or F6-TCNNQ; a metal oxide, such as a tungsten oxide or a molybdenum oxide; a cyano group-containing compound, such as Compound HT-D1 below; or any combination thereof.

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, and thus, efficiency of a formed organic light-emitting device may be improved.

Meanwhile, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be a material for the hole transport region described above, a material for a host to be explained later, or any combination thereof. For example, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be mCP.

Then, an emission layer (EML) may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the emission layer is formed by vacuum deposition or spin coating, the deposition or coating conditions may be similar to those applied in forming the hole injection layer although the deposition or coating conditions may vary according to a material that is used to form the hole transport layer.

The emission layer may include a composition including the first and second compounds described herein.

In one or more embodiments, the emission layer may include a host and a dopant, wherein the dopant may include the first compound, and the host may include the second compound.

In addition, the emission layer may further include a dopant and/or a host, other than the composition described herein.

When the organic light-emitting device 10 is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer. In some embodiments, the emission layer may have a structure in which the red emission layer, the green emission layer, and/or the blue emission layer are layered to emit white light. In some embodiments, the structure of the emission layer may vary.

When the emission layer includes the host and the dopant, an amount of the dopant may be selected from a range of about 0.01 parts to about 15 parts by weight based on about 100 parts by weight of the host, but embodiments are not limited thereto.

The thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, and in some embodiments, about 200 Å to about 600 Å. When the thickness of the emission layer is within any of these ranges, improved luminescence characteristics may be obtained without a substantial increase in driving voltage.

Next, an electron transport region may be formed on the emission layer.

The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

In some embodiments, the electron transport region may have a hole blocking layer/an electron transport layer/an electron injection layer structure or an electron transport layer/an electron injection layer structure, but embodiments are not limited thereto. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.

The conditions for forming a hole blocking layer, an electron transport layer, and an electron injection layer may be inferred based on the conditions for forming the hole injection layer.

When the electron transport region includes a hole blocking layer, the hole blocking layer may include, for example, at least one of BCP, Bphen, and BAlq:

In one or more embodiments, the hole blocking layer may include the host, a material for forming an electron transport layer to be described later, a material for forming an electron injection layer to be described later, or any combination thereof.

The thickness of the hole blocking layer may be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thickness of the hole blocking layer is within any of these ranges, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may include BCP, Bphen, TPBi, Alq₃, Balq, TAZ, NTAZ, or any combination thereof:

In some embodiments, the electron transport layer may include at least one of Compounds ET1 to ET25, but embodiments are not limited thereto:

The thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, and in some embodiments, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within any of these ranges, excellent electron transport characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may further include a material containing metal, in addition to the materials described above.

The material containing metal may include a Li complex. The Li complex may include, e.g., Compound ET-D1 (LiQ), Compound ET-D2, or a combination thereof:

The electron transport region may include an electron injection layer that facilitates electron injection from the second electrode 19.

The electron injection layer may include LiF, NaCl, CsF, Li₂O, BaO, or any combination thereof.

The thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and in some embodiments, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within any of these ranges, excellent electron injection characteristics may be obtained without a substantial increase in driving voltage.

The second electrode 19 may be on the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be a material with a relatively low work function, such as a metal, an alloy, an electrically conductive compound, and a mixture thereof. Examples of the material for forming the second electrode 19 may include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag). In some embodiments, ITO or IZO may be used to form a transmissive second electrode 19 to manufacture a top emission light-emitting device. In some embodiments, the material for forming the second electrode 19 may vary.

Hereinbefore the organic light-emitting device 10 has been described with reference to the FIGURE, but embodiments are not limited thereto.

Hereinafter, a compound and an organic light-emitting device according to an embodiment will be described in detail with reference to Synthesis Examples and Examples, however, the present disclosure is not limited thereto. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of B used was identical to an amount of A used based on molar equivalence.

EXAMPLES Synthesis Example 1 (Compound 3)

Synthesis of Intermediate L3-2

2.5 grams (g) (9.3 mmol) of 2-chloro-4-iodonicotinaldehyde was mixed with 100 milliliter (ml) of tetrahydrofuran and 30 ml of water, and 0.53 g (0.46 mmol) of Pd(PPh₃)₄, 1.3 g (9.3 mmol) of 3-fluorophenylboronic acid, and 3.2 g (23.0 mmol) of K₂CO₃ were added thereto, followed by heating under reflux at 80° C. for 24 hours. Once the reaction was complete, the reaction mixture was concentrated under reduced pressure, and dichloromethane and water were added thereto to extract an organic layer, which was then dried using magnesium sulfate and distilled under reduced pressure, followed by purification through column chromatography to obtain 1.1 g of Intermediate L3-2 (yield: 51%).

LCMS: m/z calcd for C₁₂H7ClFNO 235.02; Found 236.06.

Synthesis of Intermediate L3-1

5.8 g (17.0 mmol) of (methoxy methyl)triphenyl phosphonium chloride and 1.6 g (6.8 mmol) of Intermediate L3-2 were added to 50 ml of tetrahydrofuran and mixed. Then, at room temperature, 17 ml of 1.0 M potassium tert-butoxide solution (in THF) was slowly added dropwise thereto and stirred for 24 hours. Once the reaction was complete, water and ethyl acetate were added to the reaction mixture, and an organic layer was extracted therefrom, which was then dried using magnesium sulfate and distilled under reduced pressure. The resulting product was dried under reduced pressure, which was then mixed with 40 ml of dichloromethane. Then, 1.5 ml of methanesulfonic acid was slowly added to the mixture at room temperature, followed by stirring at room temperature for about 12 hours. Once the reaction was complete, a saturated sodium bicarbonate aqueous solution was added thereto to extract an organic layer, which was then dried using magnesium sulfate and distilled under reduced pressure, followed by purification through column chromatography to obtain 1.1 g of Intermediate L3-1 (yield: 72%).

LCMS: m/z calcd for C₁₃H7ClFN 231.03; Found 231.98.

Synthesis of Intermediate L3

0.7 g (3.0 mmol) of Intermediate L3-1 was mixed with 30 ml of THF and 10 ml of water, and 0.5 g (3.6 mmol) of 3,5-dimethylphenylboronic acid, 0.24 g (0.2 mmol) of Pd(PPh₃)₄, and 1.0 g (7.5 mmol) of K₂CO₃ were added thereto, followed by heating under reflux for one day. Once the reaction was complete, ethyl acetate and water were added thereto to extract an organic layer, which was then dried using magnesium sulfate and distilled under reduced pressure, followed by purification through column chromatography to obtain 0.72 g of Intermediate L3 (yield: 80%).

LCMS: m/z calcd for C₂₁H₁₆FN 301.13; Found 302.05.

Synthesis of Intermediate L3 Dimer

1.05 g (3.4 mmol) of Intermediate L3 and 0.6 g (1.6 mmol) of iridium chloride were mixed with 40 mL of ethoxyethanol and 15 mL of distilled water. Then, the mixture was heated under reflux for 24 hours. Once the reaction was complete, the temperature was dropped to room temperature, and the produced solid was filtered and sequentially washed with water, methanol, and hexane to a sufficient degree. The resulting solid was dried in a vacuum oven to obtain 1.0 g of Intermediate L3 dimer.

Synthesis of Compound 3

1.0 g (0.63 mmol) of Intermediate L3 Dimer, 0.96 g (4.5 mmol) of 3,7-diethylnonane-4,6-dione, and 0.48 g (4.5 mmol) of Na₂CO₃ were mixed with 40 mL of ethoxyethanol, followed by reaction by stirring at 90° C. for 24 hours. Once the reaction was complete, the temperature was cooled to room temperature, and the produced solid was filtered and purified through liquid chromatography to obtain 0.8 g of Compound 3 (yield: 65%).

LCMS: m/z calcd for C₅₅H₅₃F₂IrN₂O₂, 1004.37; Found 1005.25.

Synthesis Example 2 (Compound 9)

Synthesis of Intermediate L9

Intermediate L9 was synthesized in substantially the same manner as in Synthesis of Intermediate L3 in Synthesis Example 1, except that Intermediate L9-1 was used instead of Intermediate L3-1.

LC-MS m/z=303 (M+H)⁺

Synthesis of Intermediate L9 Dimer

Intermediate L9 Dimer was synthesized in substantially the same manner as in Synthesis of Intermediate L3 Dimer in Synthesis Example 1, except that Intermediate L9 was used instead of Intermediate L3.

Synthesis of Compound 9

Compound 9 was synthesized in substantially the same manner as in Synthesis of Compound 3 in Synthesis Example 1, except that Intermediate L9 Dimer and 3,7-diethyl-3,7-dimethylnonane-4,6-dione were used instead of Intermediate L3 Dimer and 3,7-diethylnonane-4,6-dione.

LC-MS m/z=1035 (M+H)⁺.

Synthesis Example 3 (Compound 10)

Synthesis of Intermediate L10

Intermediate L10 was synthesized in substantially the same manner as in Synthesis of Intermediate L3 in Synthesis Example 1, except that Intermediate L10-1 was used instead of Intermediate L3-1.

LCMS: m/z calcd for C₂₂H₁₆F₃N 351.36; Found 352.21.

Synthesis of Intermediate L10 Dimer

Intermediate L10 Dimer was synthesized in substantially the same manner as in Synthesis of Intermediate L3 Dimer in Synthesis Example 1, except that Intermediate L10 was used instead of Intermediate L3.

Synthesis of Compound 10

Compound 10 was synthesized in substantially the same manner as in Synthesis of Compound 3 in Synthesis Example 1, except that Intermediate L10 Dimer was used instead of Intermediate L3 Dimer.

LCMS: m/z calcd for C₅₇H₅₃F₆IrN₂O₂ 1104.35; Found 1105.40.

Example 1

A glass substrate, on which an anode having an ITO/Ag/ITO (70 Å/1,000 Å/70 Å) structure was deposited, was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm, sonicated in isopropyl alcohol and water for 5 minutes each, and cleaned by exposure to ultraviolet rays and ozone for 30 minutes. Subsequently, the glass substrate was mounted on a vacuum-deposition device.

2-TNATA was vacuum-deposited on the anode to form a hole injection layer having a thickness of 600 Å, and 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (hereinafter, referred as “NPB”) was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1,350 Å.

Subsequently, Compound H2 (host) and Compound 3 (dopant) were co-deposited on the hole transport layer at a weight ratio of 98:2 to form an emission layer having a thickness of 400 Å.

Then, BCP was vacuum-deposited on the emission layer to form a hole blocking layer having a thickness of 50 Å. Alq₃ was vacuum-deposited on the hole blocking layer to form an electron transport layer having a thickness of 350 Å. LiF was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å. Mg and Ag were co-deposited on the electron injection layer at a weight ratio of 90:10 to form a cathode having a thickness of 120 Å, thereby completing the manufacture of an organic light-emitting device (emitting red light).

Examples 2 to 6 and Comparative Examples 1 and 3

Organic light-emitting devices were manufactured in substantially the same manner as in Example 1, except that the compounds shown in Tables 1 and 2 were used instead of Compound H2 and Compound 3 as a host and a dopant in the formation of an emission layer, respectively.

Evaluation Example 1: Evaluation of Characteristics of Organic Light-Emitting Device

The driving voltage, current density, maximum of external quantum efficiency (Max EQE), FWHM of EL spectrum, emission color, color-coordinate, and lifespan (LT₉₇) of the organic light-emitting devices manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated. The results thereof are shown in Tables 1 and 2. A Keithley 2400 current voltmeter and a luminance meter (Minolta C₅-1000A) were used in the evaluation. The lifespan (LT₉₇) refers to time required for the initial luminance of 3,500 nit of the organic light-emitting device to reduce by 97%. Lifespan (LT₉₇) was shown in a relative value (%).

TABLE 1 Host Dopant Driving Current Max Color LT₉₇ Compound Compound voltage density EQE FWHM Emission coordinate (relative No. No. (V) (mA/cm²) (%) (nm) color (CIEx) value, %) Example 1 H2 3 4.45 10.7 31.5 50.9 Red 0.665, 0.332 162 Example 2 H2 9 4.8 12.2 30.8 51.6 Red 0.679, 0.32  145 Example 3 H2 10 5.02 14.5 30.0 54.5 Red 0.673, 0.323 109 Comparative H2 A 5.4 16.2 29.1 51.4 Red 0.677, 0.32  100 Example 1 Comparative H2 B 4.8 10.2 27.8 60.0 Red 0.647, 0.650 60 Example 2

TABLE 2 Host Dopant Driving Current Max Color LT₉₇ Compound Compound voltage density EQE FWHM Emission coordinate (relative No. No. (V) (mA/cm²) (%) (nm) color (CIEx) value, %) Example 4 H12 3 3.9 11.3 29.8 50.7 Red 0.667, 0.332 162 Example 5 H12 9 4.2 12.7 29.7 51 Red 0.680, 0.320 144 Example 6 H12 10 4.38 15.0 29 53.5 Red 0.674, 0.323 116 Comparative H12 A 4.6 16.9 27.1 55.8 Red 0.678, 0.320 100 Example 3

As shown in Tables 1 and 2, it was found that the organic light-emitting devices according to Examples 1 to 3 had improved driving voltage, improved EQE, and improved lifespan characteristics, as compared with the organic light-emitting devices according to Comparative Examples 1 and 2, and the organic light-emitting devices according to Examples 4 to 6 had improved driving voltage, improved EQE, and improved lifespan characteristics, as compared with the organic light-emitting devices according to Comparative Example 3.

As apparent from the foregoing description, the composition may have excellent electrical characteristics and stability. Thus, an electronic device, e.g., an organic light-emitting device, including the composition may have improved driving voltage, improved EQE, and improved lifespan characteristics.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.

While one or more embodiments have been described with reference to the FIGURES, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims. 

What is claimed is:
 1. A composition comprising a first compound and a second compound, wherein the first compound comprises a compound represented by Formula 1, and the second compound comprises a compound represented by Formula 2:

Y₂ in Formula 1 is C, a group represented by

 in Formula 1 is a group represented by Formula A(1):

wherein, in Formula A(1), R₉ and R₁₁ are each independently a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or a phenyl group, each unsubstituted or substituted with deuterium, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a phenyl group, or any combination thereof, and R₁₀ and R₁₂ are each independently hydrogen or deuterium, *′ indicates a binding site to Ir in Formula 1, and *″ indicates a binding site to a neighboring atom in Formula 1, Ar₁ in Formula 2 is a C₅-C₆, carbocyclic group unsubstituted or substituted with at least one R₆₁ or a C₁-C₆ heterocyclic group unsubstituted or substituted with at least one R₆₁, Ar₂ in Formula 2 is a π electron-depleted nitrogen-containing C₁-C₆ cyclic group unsubstituted or substituted with at least one R₆₂, Ar₅ in Formula 2 is not present or is a single bond, a C₅-C₆ carbocyclic group unsubstituted or substituted with at least one R₆₅, or a C₁-C₆ heterocyclic group unsubstituted or substituted with at least one R₆₅, n in Formula 2 is 1, 2, or 3, and when n is 1, Ar₅ is not present, a1 and a2 in Formula 2 are each independently an integer from 0 to 5, and the sum of a1 and a2 is 1 or greater, ring CY₂ and ring CY₃ in Formula 2 are each independently a C₅-C₆, carbocyclic group or a C₁-C₆ heterocyclic group, and ring CY₂ and ring CY₃ are optionally bound to each other via a C₅-C₆ carbocyclic group unsubstituted or substituted with at least one R₆₆ or a C₁-C₆ heterocyclic group unsubstituted or substituted with at least one R₆, R₁ to R₈, A₁ to A₇, R₂₀, R₃₀, R₆₁, R₆₂, R₆₅, and R₆₆ in Formulae 1 and 2 are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉), b2 and b3 in Formula 2 are each independently an integer from 0 to 20, when b2 is 2 or more, two or more R₂₀(s) are identical to or different from each other, and when b3 is 2 or more, two or more R₃₀(s) are identical to or different from each other, provided that at least one of R₁ to R₈ is a fluoro (—F) group, two or more of R₁ to R₈ in Formula 1 are optionally linked to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a), two or more of A₁ to A₇ in Formula 1 are optionally linked to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a), two or more of ring CY₂, ring CY₃, R₂₀, and R₃₀ in Formula 2 are optionally linked to form a C₅-C₆₀ carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆₀ heterocyclic group which is unsubstituted or substituted with at least one R_(1a), R_(1a) is understood by referring to the description of A₇ provided above, and a substituent of the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is: deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —Ge(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), —P(═O)(Q₁₈)(Q₁₉), —P(Q₁₈)(Q₁₉), or any combination thereof; a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —Ge(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉), —P(Q₂₈)(Q₂₉), or any combination thereof; —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —Ge(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉), or —P(Q₃₈)(Q₃₉); or any combination thereof, wherein Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ are each independently hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group, unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₂-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₂-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group, unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed polycyclic group; or a monovalent non-aromatic condensed heteropolycyclic group.
 2. The composition of claim 1, wherein R₁ to R₈ and A₁ to A₇ are each independently: hydrogen, deuterium, or —F; a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, or a phenyl group, each unsubstituted or substituted with deuterium, —F, a C₁-C₂₀alkyl group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a phenyl group, or any combination thereof; or —Si(Q₃)(Q₄)(Q₅) or —Ge(Q₃)(Q₄)(Q₅).
 3. The composition of claim 1, wherein at least one of A₁ to A₆ in Formula 1 is an unsubstituted or substituted C₂-C₆₀ alkyl group, an unsubstituted or substituted C₃-C₁₀ cycloalkyl group, or an unsubstituted or substituted C₂-C₁₀ heterocycloalkyl group.
 4. The composition of claim 1, wherein A₁ to A₆ are each independently an unsubstituted or substituted C₁-C₆₀ alkyl group, an unsubstituted or substituted C₃-C₁₀ cycloalkyl group, or an unsubstituted or substituted C₂-C₁₀ heterocycloalkyl group.
 5. The composition of claim 1, wherein a group represented by

 in Formula 1 is a group represented by one of Formulae CY1 to CY108:

wherein, in Formulae CY1 to CY108, T₂ to T₈ are each a fluoro group (—F), each of R₂ to R₈ and R_(1a) are the same as described in claim 1, provided that R₂ to R₈ are not hydrogen, * indicates a binding site to Ir in Formula 1, and *″ indicates a binding site to a neighboring atom in Formula
 1. 6. The composition of claim 1, wherein the first compound comprises at least one of Compounds 1 to 5, 8, 9, 13, 14, 25 to 29, 33 to 43 and 48 to 52:


7. The composition of claim 1, wherein Ar₁ in Formula 2 is a group derived from i) a first ring unsubstituted or substituted with at least one R₆₁, ii) a second ring unsubstituted or substituted with at least one R₆₁, iii) a condensed ring in which at least two first rings are condensed, unsubstituted or substituted with at least one R₆₁, iv) a condensed ring in which at least two second rings are condensed, unsubstituted or substituted with at least one R₆₁, or v) a condensed ring in which at least one first ring and at least one second ring are condensed, unsubstituted or substituted with at least one R₆₁, Ar₂ in Formula 2 is a group derived from i) a first ring unsubstituted or substituted with at least one R₆₂, ii) a condensed ring in which at least two first rings are condensed, unsubstituted or substituted with at least one R₆₂, or iii) a condensed ring in which at least one first ring and at least one second ring are condensed, unsubstituted or substituted with at least one R₆₂, Ar₅ in Formula 2 is not present, a single bond, or a group derived from i) a first ring unsubstituted or substituted with at least one R₆₅, ii) a second ring unsubstituted or substituted with at least one R₆₅, iii) a condensed ring in which at least two first rings are condensed, unsubstituted or substituted with at least one R₆₅, iv) a condensed ring in which at least two second rings are condensed, unsubstituted or substituted with at least one R₆₅, or v) a condensed ring in which at least one first ring and at least one second ring are condensed, unsubstituted or substituted with at least one R₆₅, ring CY₂ and ring CY₃ in Formula 2 are each independently i) a first ring, ii) a second ring, iii) a condensed ring in which at least two first rings are condensed, iv) a condensed ring in which at least two second rings are condensed, or v) a condensed ring in which at least one first ring and at least one second ring are condensed, the first ring is an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, or a thiadiazole group, and the second ring is a benzene group, a cyclopentadiene group, a pyrrole group, a furan group, a thiophene group, or a silole group.
 8. The composition of claim 1, wherein Ar₂ in Formula 2 is an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, or a pyridopyrazine group, each unsubstituted or substituted with at least one R₆₂.
 9. The composition of claim 1, wherein a2 in Formula 2 is 1 or
 2. 10. The composition of claim 1, wherein the second compound comprises a compound represented by Formula 2(1):

wherein, in Formula 2(1), Ar₅ is a single bond, a C₅-C₆, carbocyclic group unsubstituted or substituted with at least one R₆₅, or a C₁-C₆ heterocyclic group unsubstituted or substituted with at least one R₆₅, Ar₁, Ar₂, a1, a2, ring CY₂, ring CY₃, R_(1a), R₂₀, R₃₀, b2, and b3 are respectively understood by referring to the descriptions of Ar₁, Ar₂, a1, a2, ring CY₂, ring CY₃, R_(1a), R₂₀, R₃₀, b2, and b3 in claim 1, Ar₃ and Ar₄ are each independently a C₅-C₆ carbocyclic group unsubstituted or substituted with at least one R₆₁ or a C₁-C₆ heterocyclic group unsubstituted or substituted with at least one R₆₁, a3 and a4 are each independently an integer from 0 to 5, and the sum of a3 and a4 is 1 or greater, ring CY₄ and ring CY₅ are each independently a C₅-C₆, carbocyclic group or a C₁-C₆₀ heterocyclic group, and ring CY4 and ring CY₅ are optionally bound to each other via a C₅-C₆ carbocyclic group unsubstituted or substituted with at least one R₆₆ or a C₁-C₆ heterocyclic group unsubstituted or substituted with at least one R₆₆, two or more of ring CY4, ring CY₅, R₄₀, and R₅₀ are optionally linked to form a C₅-C₆, carbocyclic group which is unsubstituted or substituted with at least one R_(1a) or a C₁-C₆, heterocyclic group which is unsubstituted or substituted with at least one R_(1a), R₄₀ and R₅₀ are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉), and b4 and b5 in Formula 2 are each independently an integer from 0 to 20, when b4 is 2 or more, two or more R₄₀(s) are identical to or different from each other, and when b5 is 2 or more, two or more R₅₀(s) are identical to or different from each other, a substituent of the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is: deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —Ge(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), —P(═O)(Q₁₈)(Q₁₉), —P(Q₁₈)(Q₁₉), or any combination thereof; a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₂-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —Ge(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉), —P(Q₂₈)(Q₂₉), or any combination thereof; —N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —Ge(Q₃₃)(Q)(Q₃₅), —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉), or —P(Q₃₈)(Q₃₉); or any combination thereof, wherein Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ are each independently hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group, unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₂-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₂-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group, unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group; a monovalent non-aromatic condensed polycyclic group; or a monovalent non-aromatic condensed heteropolycyclic group.
 11. The composition of claim 1, wherein a group represented by

in Formula 2 is a group represented by one of Formulae 2-1 to 2-93:

wherein, in Formulae 2-1 to 2-93, X₁ is O, S, N(R₃₁), C(R₃₁)(R₃₂), or Si(R₃₁)(R₃₂), X₂ is O, S, N(R₃₃), C(R₃₃)(R₃₄), or Si(R₃₃)(R₃₄), R₃₁ to R₃₄ are each understood by referring to the description of R₃₀ in claim 1, and * in Formula 2 indicates a binding site to Ar₁ or Ar₂.
 12. The composition of claim 1, wherein Ar₂ in Formula 2 is a group represented by one of Formulae 5-1 to 5-31:

wherein, in Formulae 5-1 to 5-31, R₆₂ is understood by referring to the description of R₆₂ in claim 1, c2 is an integer from 0 to 2, c3 is an integer from 0 to 3, c4 is an integer from 0 to 4, c5 is an integer from 0 to 5, c7 is an integer from 0 to 7, and * indicates a binding site to Ar₁ or N in Formula
 2. 13. The composition of claim 1, wherein the second compound comprises at least one of Compounds H1 to H90:


14. An organic light-emitting device comprising: a first electrode; a second electrode; and an organic layer between the first electrode and the second electrode and comprising an emission layer and the composition of claim
 1. 15. The organic light-emitting device of claim 14, wherein the first electrode is an anode, the second electrode is a cathode, and the organic layer further comprises a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode, the hole transport region comprises a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof, and the electron transport region comprises a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
 16. The organic light-emitting device of claim 14, wherein the composition is comprised in the emission layer.
 17. The organic light-emitting device of claim 14, wherein the emission layer emits red light. 